The present invention relates to a novel design for golf equipment, and more particularly to a golf club head with an improved configuration which affords greater stability and control by the golfer.
The history of golf can be traced to Scotland, where the first recorded games occurred in the fifteenth century. There is evidence that there may have been a Dutch antecedent to the game that evolved in Scotland. Codified rules for playing golf have existed since the mid-eighteenth century.
Today, the sport of golf provides a challenging diversion for people around the world, of all ages. It is chosen by many because performance and success are not solely dependent upon strength, but in addition require experience, discipline, and control. This is evidenced by the triumph of older golfers over younger ones in tournament and social play. That is, while sheer brawn can enable a golfer to hit or "drive" the golf ball the long distances traversed during a game, equipment is available today to help compensate for a lack of great physical strength by the golfer. Thus, the present day golfer does not require a powerful "swing" for success but must rely more on strategy and practiced control.
The object of golf is to use a "club" to hit a golf ball from the "teeing" area into a hole or "cup" located in a "putting" area which is several hundred yards away. In the U.S., the ball is 1.68" in diameter, and the hole has a cylindrical shape that is 41/4" in diameter and at least 4" deep. Each segment composed of a teeing and putting area is also commonly referred to as a "hole", and a game or "round" may include either nine or eighteen holes.
A golf course typically consists of grassy areas for teeing and putting, and grassy areas along the "fairway". "Hazards" comprised of water and/or sand serve to challenge the golfer and are also located along the fairway. The winner of a game, or a tournament involving several games, is the golfer who manages to finish using the fewest "strokes" of his or her clubs. The proper "form" for golfing is generally comprised of 1) proper "addressing" or alignment of the ball with the club, 2) a full back- and through swing to gain club speed, and 3) precise, square impact of the ball with the "head" of the golf club.
The trajectory or path of the golf ball is determined by both the momentum of and the point of contact with the club head. Except when hitting out of a sand trap, the club head and ball make direct contact. A vector is formed by the initial direction and speed of the golf ball and results from the ball's contact with the front "face" of the head. It is this vector which must be precisely controlled by the golfer for accurate placement of the ball toward the cup. From the teeing area, it is desirable to control the ball so that it stays on the open fairway and avoids any hazards. Control in putting is especially important in order to get the ball to follow the "line", which is the correct path to the cup from an initial lie or position, and depends on the condition of the playing surface. Ideally in putting, the golfer only needs to provide an initial rolling motion of the ball along the line and it will follow the line into the cup.
A golfer requires a basic set of clubs for the various situations he or she will usually encounter. The basic assortment of golf clubs required to play a game includes the broad classifications of "drivers", "irons", and "putters". The purpose of each type of club is to provide a specific initial angle for the trajectory of the ball, in addition to providing enough energy to achieve a specific distance. Drivers are used to hit the ball the longest distances, hopefully without veering far off the fairway or encountering a hazard. Irons are used to control a golf ball with more vertical than horizontal travel, possibly to clear a hazard, and gain a more advantageous position on the grassy fairway or putting green. Putters are used once on the putting green either for an "approach shot" to get close to the cup or to "hole-out" by landing the ball into the cup and finishing that hole.
Today's golf clubs can vary widely in design. Generally, however, all clubs are comprised of portions referred to, from top to bottom, as the grip or handle, the shaft, and the head. The handle is formed by wrapping leather, rubber, or other synthetic material to encase the gripping end of the shaft, which is held by the golfer. The other end of the long, thin, tubular shaft is attached to the head. The shaft may be stainless steel or a graphite composite, and it may be longer or shorter for specific distance or range control. The basic types of clubs can generally be identified by their head design and shaft length.
Originally, club heads, as well as shafts, were made of wood. Today, although a few wood heads are still available, club heads are usually made of metal. The head or club types may be grouped as irons, "woods" and "metal woods", and putters. Generally, drivers for the 200 yard and greater range are woods and metal woods, and wedges and drivers for shorter ranges are irons. A "ferrule" portion may be located above the "hosel", or neck portion of the head, on the shaft of irons. The ferrule is a short, decorative, sleeve-like cap. Woods may include "whipping" above the hosel. The whipping is formed by thin laces of leather or other material which are wrapped around the shaft numerous times.
In the construction of a golf club, the hosel has a socket into which the shaft is inserted and secured. The hosel is often formed integrally with the head and is contiguous with the "heel" or proximal end of the head. The hosel may also be formed as a separate portion attached to the top of the head and aligned above the heel. Thus, the shaft and hosel are traditionally in a "top to bottom" configuration with the head. That is, the shaft, hosel, and club head are generally vertically aligned, with the golfer effectively "pushing" the club head through the stroke.
The axis of the shaft may be collinear with the hosel and thus behind the front face. Or, in the case of putters, the shaft may be slightly displaced in front of the face. In the latter case, the hosel is angled below the socket and goes down into the top of the head above the heel, yielding essentially the same top to bottom configuration. This slight displacement of the shaft to a location in front of the face does result in a "line of sight" which allows somewhat more accurate positioning of the club by the golfer. However, the shaft axis is still generally positioned between the center of the ball and the face of the club.
The face of the club head is intended to hit the golf ball. A golfer who hits the ball with the hosel of the head, instead of the face, is said to "shank" the ball, which results in a wild, uncontrolled golf shot. The face may have a pattern of grooves to reduce possible rolling contact with the ball. Also, the face may be marked or painted to note the area of the "sweet spot", which is centrally located. This area is called the sweet spot since it is the ideal location for imparting the desired momentum or energy to the ball. The sweet spot generally marks the center of mass for the club head and can vary from a small to a major portion of the face.
Another part of the club head is the "sole", which is the bottom surface. The sole may be of varying area, depending on the head design. The sole for a driver is often of a convex shape, to minimize contact of the head with the ground during the stroke, since this can change the momentum imparted to the ball. The sole for a blade-shaped putter is substantially narrower and of smaller total area.
The back portion of the head, behind the face and above the sole, can be thick and bulbous or thin and narrow. The former is characteristic of woods and metal woods. The latter is characteristic of irons and putters. The backs of irons and putters may also be formed of "struts" and "cavities" which form hollow areas and reduce the total mass at the back of the head. In recent designs, "peripheral weighting" is used to concentrate the head's mass around the face, which results in a back portion that may be either recessed or made bulky by using a lightweight "filler" medium.
The last part of the head is the "toe" or the end of the head opposite the heel. The toe end is sometimes referred to as the "nose". This end will be referred to herein as the distal end of the head.
In golf, energy is transferred to the ball by the momentum of the club, and specifically by the club head's momentum. Linear momentum is derived as an object's mass multiplied by its velocity (P=m.times.V). Linear or tangential velocity at a point on a curve is found from the angular speed and the radius at that point (V=.omega..times.r). The maximum momentum (P=m.times..omega..times.r) or energy for driving long distances is achieved by using a club with a large head (m) on a long shaft (r) along with a full "backswing" and downswing (.omega.). Alternately, for shorter distances, a smaller head and/or shorter shaft is used, sometimes with smaller swinging movements. A putter head may be either "blade" or "mallet" shaped, although still of smaller overall mass and dimension than the head of a driver.
Golf clubs are further distinguished by the "lie" and the "loft" of the club head. The lie is the angle formed by the shaft and hosel with the horizon. Typically, as the lie gets smaller, the shaft of the club gets longer to allow a wider swing path and thus greater velocity. The loft is the angle formed by the face of the head with the vertical, where the vertical is defined herein as perpendicular to the horizon. A greater loft corresponds to greater vertical, rather than horizontal, travel of the ball.
For example, a putter will generally have a relatively short shaft, and the putter head will have close to a 90 degree or "upright" lie and a nearly zero degree or "straightfaced" loft. These specifications help to impart a controlled, horizontal force to the ball, as is desirable for putting. Alternately, drivers and irons are designed to have longer shafts and heads with smaller lies. Also, these heads have lofts ranging from approximately 8 degrees to up to 60 degrees, all of which help to deliver an upward force to the ball and make it airborne for a majority of its travel.
As mentioned above, there are existing designs for clubs which enhance the total energy delivered by the golfer's backswing, downswing, and "followthrough". These clubs provide delivery of the golf ball over two hundred yards by enlarging the head's mass and also the available sweet spot on the head. However, there are few club designs which attempt to improve the golfer's control over his or her stroke and the ball. This control is particularly important for putting, where the final, short distance must be carefully navigated in order to place the ball at least near, if not in, the cup. Thus, there is a need to provide equipment which improves the golfer's control over the trajectory of the ball.